There is no precise method to divide the Vietnam War into convenient phases. However, from the standpoint of an airmobility study, one can consider the first phase as a learning period—a time when U. S. Army pilots were teaching Army of the Republic of Vietnam commanders and soldiers how to effectively employ helicopter tactics, while at the same time the pilots were learning by experience, trial and error. As more and more helicopters became available, we built additional aviation units to help the Vietnamese Army become as mobile as the enemy.

This second phase of the war was characterized by battalion-size air assaults of selected Vietnamese units, including the paratroopers, the rangers, and the regular infantry. It was the success of this phase that forced the enemy to increase his effort in South Vietnam. This proved to be something that the North Vietnamese Army was quite ready to do, and the improved capabilities of the Army of the Republic of Vietnam were matched step-by-step with increased resistance of the Viet Cong and North Vietnamese Army, as additional units and supplies poured down the Ho Chi Minh Trail complex and across the border. It was during this second phase that we made great improvements on our tactical employment of helicopters. It was also during this period that we created our own airmobile division, tested it, and concluded that in terms of ground tactics, airmobility was here to stay. We studied the variety of tactics used by the Vietnamese and their U. S. support in these airmobile operations of extended scope and we tried to apply everything we learned to the organization and training of our airmobile units.

It was also during this second phase that the Huey came into its own. The turbine engine helicopter with its great power, its reliability, and its smaller requirement for maintenance, was the technological turning point as far as airmobility is concerned. Actually, the key improvement of technology was the trio of the

Huey as a troop lift bird, the Chinook with its larger capacity for resupply and movement of artillery, and the fledgling attack helicopter-these three together allowed us to take a giant step forward at this time.

From the time of the first major commitment of helicopters to Vietnam on 11 December 1961 until the buildup of major U. S. forces in 1965, airmobility was—like diplomacy—confined to the art of the possible. The early helicopters were old and unsuited for this particular mission; the rules of engagement were set by the South Vietnamese Government—a Government that was continually changing in a series of coups and counter-coups; and the Viet Cong was undergoing a phenomenal period of growth.

The primary mission of U. S. military forces was to advise and assist the Republic of Vietnam Armed Forces to build a viable military structure to meet the needs of its national security. Because of the increasing scope and intensity of Viet Cong operations, this advisory task expanded very rapidly during this period. The Viet Cong regular force grew steadily from two to five regimental headquarters, the Viet Cong battalions doubled in the same period, and the quality and quantity of their weapons and equipment improved considerably. This build up necessitated the deployment of additional U. S. Army aviation units to support Government of Vietnam forces. From a single transportation battalion with three helicopter companies in early 1962, the U. S. Army developed an enormous operational and logistical support complex consisting of many battalions of helicopter companies, fixed-wing units, maintenance units, and special purpose organizations.

It is interesting to note how the enemy viewed this increasing airmobility potential. The following is a translation of an extract from a North Vietnamese instruction pamphlet captured on 16 November 1962:

It is obvious that the Viet Cong, in spite of all their polemics, had recognized that the advent of airmobility in Vietnam had changed the name of the game. True, the allies had much to learn about the employment of this new capability, but the war would never be the same.

It is important to recognize that the early airmobility efforts with the H-21 and Army of the Republic of Vietnam personnel represented the lowest order of airmobility . . . that is, simply transporting people from point "A" to point "B". This is analogous to the requisitions of French taxis in World War I. It provided better and faster transportation than walking. But, it lacked the essentials of unified command, specially trained personnel, organic firepower, and responsive reconnaissance.

The early Army aviators in 1962 spent a great deal of their time simply training the Vietnamese in the rudiments of getting in and out of a helicopter and conducting themselves properly in a landing zone. This was further complicated by fuzzy command relationships. The U. S. Army helicopter pilot belonged to Military Assistance Command, Vietnam, and was attached to the U. S. advisor on a one-time mission basis. The aircraft commander still had the authority to abort a mission that he did not feel safe; yet, he was not in the early planning phases and did not share the responsibility of the success or failure of the mission. Furthermore, he did not control the tactical air support or artillery fire nor the timing thereof. It is easy to understand the frustrations some of the early relationships generated.

Little by little, sheer necessity forced those in-country to make workable agreements on standing operating procedures. The "who-does-what-to-whom" on command and control, flight levels, and fire support were among the most important procedures agreed upon. The evolution of a command and control helicopter, carrying all the essential commanders and liaison officers plus the proper communications equipment, soon came about. Armed helicopters would soon be part and parcel of every transport column-and the polywog shape of the Huey would soon become the universally recognized silhouette in Southeast Asia.¹

1. The transition to the Huey had its beginning in January 1955 when a design competition was held to select the new standard Army utility helicopter. The first model, designated the XH-40, flew in 1956 and the UH-1B model did not begin its user evaluation testing until 28 November 1960. By June of 1963, most of the light helicopter companies had phased in the new UH-1B helicopters and had transitioned their aviators, maintenance personnel, and crew chiefs to the new aircraft. But, it would not be until 27 June 1964 that the last tired old CH-21 was formally retired by General Oden, Acting Commanding General, U, S. Army Support Command, Vietnam. These times tend to give some appreciation of the long lead time necessary to develop and prove a new helicopter.

Early attempts had been made to arm the CH-21 with a light machine gun at the door, but this fire was relatively ineffective. To better meet this requirement, the Army formed the Utility Tactical Transport Helicopter Company and deployed it to Vietnam in mid-1962. This company was equipped with UH-1 helicopters armed with .30-caliber machine guns and 2.75-inch rocket launchers and was designed to provide protective fires for the CH-21 transport helicopters. Much of the tactical doctrine for armed helicopter employment evolved during this period including the techniques for protective fire preparation of landing zones prior to and during a helicopter assault. The Utility Tactical Transport Helicopter Company was redesignated the 68th Aviation Company and later the 197th Airmobile Company. Its early history was studied intensely by a special group known as the Army Concept Team in Vietnam which was established in Saigon on 6 November 1962.

General Rowny, after duty with the Howze Board, had been designated to form the Army Concept Team in Vietnam by the Chief of Staff of the Army with the mission to evaluate new methods of countering insurgency in actual combat. The Army Concept Team in Vietnam had a variety of projects to include rotary and fixed-wing aircraft, communications, armored personnel carriers, logistics, and civic action tests. Fortunately for the purpose of this study, they were able to document the early attempts at airmobility in a special and objective way.

One of the most important reports made by General Rowny's Army Concept Team in Vietnam evaluators was their analysis of the effectiveness of the armed helicopter company during the period 16 October 1962 through 15 March 1963. This test unit had a dual mission in that it was actually fighting a real war and providing armed protection for the transport helicopters, while, at the same time, it provided data to the evaluators (who sometimes were heavily engaged in combat themselves).

The first element of fifteen armed Hueys was deployed to Vietnam in September 1962. To assure proper employment, General Rowny hammered out a modus operandi with Military Assistance Command, Vietnam, on 29 September 1962, which provided a framework for the forthcoming test. The terms of reference provided that the test activities must not have an unacceptable impact on military operations. Therefore, testing was undertaken only in conjunction with actual operations, and in no case was the test

unit required to engage in activities designed solely for test purposes.

More fundamental limitations were the rules of engagement for U.S. Army armed helicopters, which precluded testing of any tactical concepts involving "offensive" employment. Under these rules, the armed helicopters could deliver fire only after they or the escorted transport helicopters had been fired upon. In late February 1963 the rules were modified to permit the armed helicopters to initiate fire against clearly identified insurgents who threatened their safety or the safety of escorted transport helicopters.

Initially, the fifteen UH-1A helicopters were armed with locally fabricated weapons systems consisting of two .30 caliber machine guns and sixteen 2.75-inch rockets. In November 1962 the unit was augmented with eleven UH-1B helicopters. The "B's" were equipped with factory installed weapons systems of four M-60 machine guns per aircraft and locally fabricated clusters of eight 2.75-inch rockets. The "B" model eventually replaced most of the less powerful "A's."

The provisional Utility Tactical Transport Helicopter company was based at Tan Son Nhut Airport on the outskirts of Saigon and was under the direct operational control of Military Assistance Command, Vietnam. From this base, it supported transport operations of the 57th, 33d, and 93d Light Helicopter Companies, all equipped with CH-21 aircraft. In the latter part of the test period, one platoon of helicopters was sent to escort the Marine H-34 squadron operating in I Corps.

The plan of test for this company called for the evaluation of the armed helicopter in the "escort" role. Although "escort" was not defined, actual experience determined that the escort role broke down into an enroute phase, that was generally flown at a relatively safe altitude, the approach phase, where the heliborne force usually descended to nap-of-the-earth heights several kilometers away from the landing zone, and the landing zone phase. It was in the landing zone phase that the armed helicopter proved most valuable.

Prior to the advent of the escort by the Utility Tactical Transport Helicopter company, transport helicopters on the "dangerous" combat support missions were being hit at a rate of .011 hits per flying hour. For similar missions escorted by the Utility Tactical Transport Helicopter company, the rate declined to .0074. During this same period of time, the hit rate for all other flying done by Army helicopters rose from .0011 to .0024. In other words, the Viet Cong effectiveness against unescorted aircraft doubled while

the efficacy of their fire against escorted aircraft dropped by 25 percent. Consequently, it was concluded that the suppressive fires delivered by armed escort helicopters were highly effective in reducing the amount and accuracy of enemy fires placed on transport helicopters. The response of the transport helicopter pilots to this added protection was clearly enthusiastic. Even the skeptical Marine pilots began to rely heavily on the Army armed helicopters.

Although the safety of the transport helicopters was the primary consideration in escort operations, the vulnerability of the escorts themselves was a matter of concern. The escorts preceded the transports into the landing zone and remained until all transports had departed. When the landing zone was small and the transport force used an extended formation, the period of exposure for armed escorts was unnecessarily long. The escorts generally flew at no more than 100 or 200 feet above the ground and were well within the zone of maximum vulnerability from small arms.

The Utility Tactical Transport Helicopter company flew 1,779 combat support hours from 16 October 1962 through 15 March 1963. Most of the operations were conducted in the III and IV Corps Tactical Zones. Suppressive fire delivered by the escort helicopters accounted for an estimated 246 Viet Cong casualties. During this period, eleven armed helicopters were hit by hostile fire. While no armed helicopter was shot down, one UH-1B was seriously damaged as a result of ground fire. It appeared that the vulnerability of armed helicopters was well within acceptable risk limits.

The first official Air Force recognition of the role of armed helicopters, and their first attempt to regulate their use in Vietnam, appeared in a document dated 27 December 1962, entitled "Helicopter Escort," and signed by Brigadier General Rollen H. Anthis, Commander of the Second Air Division. Generally, the armed helicopter was limited to one minute of fire before the transport helicopters landed and one minute after the last departed.

This arrangement proved unworkable and the Army continually sought more flexible guidelines. The Air Force consistently main-

tained the helicopter must be limited to strictly defensive fires and they were quick to report to Military Assistance Command, Vietnam, of an incident where the Army in their opinion usurped the role of close support. For example, on 26 July 1963, the Second Air Division wrote a letter to General Paul D. Harkins stating that, in three recent incidents, Army helicopters were used "offensively." Further, the Air Division inferred that: ". . . Employment of the HU-1B's in the above incidents appears to be an expansion of your directive for the use of armed helicopters to include interdiction and close air support missions. It also appears that air requests are being stopped prior to arrival at the ASOC's, with subsequent substitution of U. S. Army aircraft from Corps Advisor and Division Advisor resources."

Major General Richard G. Weede, USMC, Chief of Staff, Military Assistance Command, Vietnam, replied:

By mid-1963 the 1st Platoon of the Utility Tactical Transport Helicopter Company which worked with the Marine H-34's in the I Corps sector had become adopted by their comrades-in-arms as an integral part of their operations and few, if any, H-34 pilots elected to fly without the armed Hueys nearby. Procedures were developed whereby the armed Hueys picked up the fire support right after the fixed-wing fighter planes broke off their support for safety reasons, and that, in most cases, the last minute reconnaissance by the armed helicopters prevented the Marine H-34 from going into extremely hot ambushed landing zones.

Ironically during this same period, I found myself as Director of Army Aviation testifying in front of Congressional committees on the role and absolute necessity of more and better armed helicopters. The Commandant of the Marine Corps and various Air Force officers gave negative testimony on the merits of this system. Fortunately, the Army viewpoint prevailed.

After the tests of the armed helicopter and the Utility Tactical Transport Helicopter company were concluded and more Hueys became available for replacing the CH-21, the Department of the Army decided to convert the helicopter companies within Vietnam to a new airmobile company Table of Organization and Equipment. Each of the airmobile companies was organized into one armed platoon consisting of eight UH-1B helicopters with installed weapons systems and two transport platoons with eight UH-1B helicopters each. The Utility Tactical Transport helicopter company remained in-country and supported the Marines and U. S. Army units without organic armed helicopters.

The early tests with the Utility Tactical Transport helicopter company indicated that a platoon from five to seven armed helicopters could protect a transport helicopter force of from twenty to twenty-five aircraft. The organization of the new airmobile company was a compromise between the requirement to provide organic arms support and the requirement to lift troops and cargo.

The armament system brought the armed UH-1B up to its maximum gross weight thereby eliminating it from a troop or cargo-carrying role. In addition to the integrated machine gun and rocket systems, two door gunners were used on the armed helicopters. The door gunners provided additional fire when a threat was clearly identified, and they also performed the functions of clearing and reloading weapons between engagements and clearing some stoppages during engagements.

The UH-1B was not designed for an armed configuration and the weight of the armament system reduced the maneuverability of the aircraft and induced sufficient drag to lower the maximum speed to approximately 80 knots. As a consequence, the armed helicopters could not overtake the airmobile force if they left the formation to attack targets enroute. The early armed UH-1B's did an outstanding job in proving the concept of the armed helicopters, but they also pointed out many deficiencies that the Army would correct in later versions.

Some basic operating procedures became standard. When a target was identified, the escort leader determined whether it could be attacked under the rules of engagement and, if so, directed the engagement. Where possible, targets were engaged at the maximum range of the weapon. This usually consisted of a continuous burst of machine gun fire throughout each firing run. The flight pattern

was so planned that when the lead aircraft completed its firing run the next aircraft was in position to engage the target. This tactic placed continuous fire on the target until it was neutralized. Rocket fire was used when necessary to reinforce the fires of the machine guns.

The techniques of fire for all weapons systems were based on maneuvering the helicopter and manipulating the weapons during the firing run. The flexibility of the armed helicopter's weapons systems allowed targets to be engaged without a requirement to maintain the armed helicopter on an aircraft-to-target line. This feature was exploited whenever possible to minimize helicopter exposure to the target engaged. When using rockets to attack targets obscured by trees or overhanging foliage, it was found that best results were obtained with a delayed fuse.

Fire of the armed escort helicopters during the enroute phase was controlled by the armed escort leader. The pre-mission briefings identified the probable insurgent areas and prescribed fire control procedures to be used by both the armed escorts and transports enroute and during the landing phase. In the landing zone, before friendly troops were on the ground, armed escort fire was controlled by the escort leader. After the ground force arrived in the landing zone, the ground commander often marked and identified insurgent targets so that suppressive fire could be quickly and accurately placed on them. On medical evacuation missions and other missions of this type, when the ground unit was in control of the landing zone, the fire of the helicopters was controlled by the ground commander. He designated targets, marked friendly areas, and determined if escort fire could be used without endangering friendly forces. In mountain and jungle terrain, where targets were obscured, the suppressive fire had to be accurately controlled and fire discipline maintained in order to avoid hitting friendly troops and to prevent needless expenditure of ammunition.

The armed escort was under operational control of the transport commander during the enroute and landing phases of airmobile operations. If the armed escort remained in support of the troops in the landing zone, the ground commander assumed operational control.

During this period of time opinion varied on the necessity for door gunners on transport helicopters. Generally speaking, those not close to the action favored elimination of the door gunner for the additional weight and space, while the transport helicopter pilots favored the retention of the door gunner without exception.

In mid-1963 the question of camouflaging the helicopters arose. Both camouflaged and uncamouflaged helicopters were used by U. S. Army units. Some pilots reported that the camouflaged helicopters were more difficult to see especially in mountainous terrain and a pilot spent an undue amount of his time keeping track of his other ships. Other pilots and evaluators expressed the opinion that the white Army markings and the yellow rings on the tails of the uncamouflaged helicopters were of value to the enemy gunners for the purpose of aiming and tracking. By and large, it was determined that the advantages of camouflage outweighed the disadvantages.

When the UH-1B transport helicopter was first introduced in Vietnam, it usually carried ten combat-equipped Vietnamese soldiers and at times as many as eleven. An investigation determined that the average helicopter was grossly overloaded with this many soldiers. A combat-equipped Vietnamese soldier averaged 167 pounds. When ten personnel were loaded into the Huey with a

full fuel load, a U. S. Army crew of four, armor plate, a tool box, a container of water, a case of emergency rations, weapons, armored vests for the crew, the Huey grossed 8,700 pounds, or 2,100 pounds over normal gross weight and 200 pounds over the maximum operational weight. Not only that, the center of gravity had shifted beyond safe limits. As a consequence, the standard procedure was to limit the UH-1B to eight combat troops except in grave emergencies. It was also directed that the armed helicopters would carry no more than the normal complement of five personnel and armament with the basic load.

It was the company commander's responsibility to insure that the helicopters were not overloaded and that they remained within maximum allowable weight and center of gravity limitations. However, because of operating requirements, the pilot was delegated this responsibility and would estimate the load to be lifted, supervise loading and tie-down, and insure that the aircraft was safe for flight. To verify the estimated safety factor, the helicopter was brought to a hover to check available cycling range and power prior to departure.

During 1963 the single most important factor in the development of tactics, techniques, and procedures for airmobile units in the Republic of Vietnam was the lack of significant enemy air defense capabilities, either ground or air. The ground-based threat was essentially hand-held small arms and automatic weapons fire. On rare occasions caliber .50 or 12.7-mm machine gun fire was encountered. The lack of heavy enemy air defense had much to do with the selection of flight altitudes. During this time frame, most flights were made at 1500 feet or higher to reduce the chances of being hit by ground fire. Contour flying was rarely performed. The Viet Cong continued to ambush landing zones, especially in mountains or mangrove areas where there was a very limited number of landing sites. On occasion, they would mine the area or drive stakes to prohibit landing. Most of the resistance, not surprisingly, was in the critical landing phase of an air assault mission.

The planning for an airmobile assault had evolved rather rapidly from the haphazard coordination witnessed in early 1962. Usually, this planning was initiated when the aviation battalion received a mission request from the Corps Tactical Operations Center. Missions were then assigned to the aviation companies by the aviation battalion commander. The companies usually received

daily mission requirements by 1800 hours on the previous evening. However, standing operation, procedures were such that a mission could be initiated in less than an hour if necessary.

If time permitted, an aerial reconnaissance was conducted by the airmobile company commanding officer, a representative of the aviation battalion, and a representative from the supported unit. During the reconnaissance, approach and departure routes were selected, condition and size of the landing zone were noted, and flight formations, check points, and altitudes to be flown were determined. Reconnaissance air traffic over the intended landing zone was closely controlled in order to achieve the element of surprise.

Various companies used different helicopter formations enroute to a combat assault. A major consideration in the selection of a formation was the size and shape of a landing zone and the company commander's requirements for disembarking his troops after landing. A modified trail formation was sometimes used when an uninterrupted flow of troops into a small landing area was desired. The formation most frequently used was the "V". This formation proved to be versatile, easy to control, and permitted landing of the flight in a minimum of time without bunching. Helicopters normally flew about 45 degrees to the side and rear of the lead ship and high enough to be out of the rotor wash. Armed helicopters operated at the same altitude as the escorted force. A reconnaissance element of two or four armed helicopters preceded the transports by one to five minutes while the remaining escorts normally flanked the transports in a trail formation. If additional armed ships were available, they were positioned in the rear of the transports to engage targets under the flight.

The helicopter companies always attempted to plan return routes that were different from the approach routes. For subsequent lifts routes were varied slightly to avoid flying over a given area more than once. If one landing zone was used several times, the final approach and entry for each lift was varied if at all possible. In mountainous areas and in some jungle areas, it was not possible to vary the route of approach. Consequently, every attempt was made to land the troops in the shortest possible time to minimize danger.

Any deviation from the original air movement or landing plan was co-ordinated with the commander of the air-lifted force prior to execution. If the landing zone was heavily defended the mission commander could notify the commander of the air-lifted force and proceed to a pre-planned alternate landing zone.

The critical approach phase was initiated by all transport helicopters at the same time in an attempt to place all aircraft on the ground simultaneously. This was difficult to accomplish because of the stepped altitude of the formation, the rotor wash encountered during descent, and the difficulty in finding a suitable touchdown spot for each ship. However, it remained a goal. The terrain in the landing zone sometimes slowed the disembarking of troops. In the Delta, water was sometimes chest deep and the ship had to be held with the skids just under the water level or had to maintain a low hover. In jungle areas, grass ten to twelve feet high was often encountered. From the moment the first helicopter touched down until the last ship lifted off, two minutes were considered average unloading time for a twelve-ship formation. This two minutes seems an eternity when one is expecting enemy fire any second.

To lessen the possibility of fire being concentrated on a single ship, all helicopters attempted to depart at the same time. Direction of take off was varied for subsequent flights whenever possible. The armed escorts used the same tactics on the return route with the exception that the ships originally used for the reconnaissance were the last to leave the landing zone and consequently usually brought up the rear. If another lift was required, the formation returned to the loading area for troops and, if necessary, the aircraft were refueled and rearmed.

Perhaps the foregoing planning considerations sound trite to today's informed reader. But one must bear in mind that to the airmobile commander of 1963 they represented the distillations of many hard-learned lessons and the planning procedures were quite sophisticated for the situation. Even then they were being refined.

In an effort to reduce the planning time required for executing an air assault mission, some of the earlier helicopter units developed a task force called an "EAGLE FLIGHT". An "EAGLE FLIGHT" was defined by Headquarters U. S. Military Assistance Command, Vietnam, as "a tactical concept involving the employment of a small, self-contained, highly-trained heliborne force. Tactical planning emphasizes the use of this force to locate and engage the enemy or to pursue and attack an enemy fleeing a larger friendly force. As an airmobile force, 'EAGLE' is also prepared to engage an enemy force located or fixed by other friendly forces. The inherent flexibility of the 'EAGLE FLIGHT' as a force ready for immediate com-

mitment either alone or in conjunction with other forces is its most significant factor."

A typical EAGLE FLIGHT would consist of the following: one armed Huey would serve as the command and control ship and would have the U.S. Army aviation commander and the Army of the Republic of Vietnam troop commander aboard; seven unarmed Hueys were used to transport the combat elements; five armed Hueys gave the fire support and escort to the troop-carrying helicopters; and, one Huey was usually designated as a medical evacuation ship.

The EAGLE FLIGHTS were usually on a standby basis or sometimes even airborne searching for their own targets. Not only were these EAGLE FLIGHTS immediately available for those missions which required a minimum of planning, but they also provided the basis for larger operations. Several EAGLE FLIGHTS were sometimes used against targets that, when developed, proved too large for a single unit.

By November 1964, all helicopter companies in South Vietnam had organized their own EAGLE FLIGHTS and each company maintained at least one flight in an alert status on a continuing basis. The Vietnamese troop commanders were particularly enthusiastic about these operations for they provided a very close working relationship between the air and ground elements and a special esprit was built from the day-to-day operations.

Simply stated, the EAGLE FLIGHT was a microcosm of the large airmobile assaults that were destined to take place later. It had all the attributes of a true airmobile force with its self-contained reconnaissance and surveillance ability, firepower, and Infantry. Above all, these early EAGLE FLIGHTS were able to capitalize on the element of surprise which so often was lost in the detailed planning cycle with Army of the Republic of Vietnam forces.

At the beginning of 1964 the United States had 388 aircraft in Vietnam including 248 helicopters, too few to accommodate the expanding advisory effort and increasing Vietnamese Army operations. By the end of September 1964, there was in South Vietnam a total of 406 Army aviation aircraft supporting the Army of the Republic of Vietnam as follows:

To support this effort, a total of 3,755 Army aviation personnel were provided consisting of 780 officers and 2,975 enlisted personnel. This made it possible to place a U.S. Army aviation company or a U.S. Marine Corps aviation squadron in support of each Vietnamese Army division with additional aviation supporting each Corps.

As 1964 came to a close, the U.S. Army support in Vietnam consisted of these major organizations: the 13th Aviation Battalion at Can Tho supported the IV Corps area with three Huey companies and one Birddog platoon; the 145th Aviation Battalion at Saigon supported the III Corps area with two Huey companies and one armed helicopter company; the 52d Aviation Battalion at Pleiku supported I and II Corps areas with two Huey companies, one Birddog platoon and one Caribou platoon; the 14th Aviation Battalion at Nha Trang supported all of South Vietnam and Thailand with one direct support maintenance company, one fixed-wing Otter company, and one Birddog platoon; the 765th Transportation Battalion at Vung Tau supported all four aviation battalions with two direct support maintenance companies, one general support maintenance company, one Caribou company, and one Special Warfare aviation detachment of Mohawks; and, finally, the Special Forces Group was supported with miscellaneous Army aircraft.

Since I discussed earlier the controversial aspects of the Mohawk in its relation to the Army-Air Force roles and missions issues, it is important to review its actual performance in Vietnam in 1962. The six armed Mohawks did a magnificent job and many Army advisors pleaded for more of the same. The missions performed by these aircraft during this period were somewhat tangential to the story of airmobility in the Army. However, this does not take anything away from the individual accomplishments of the Mohawk pilots.

After a storm of controversy in the Pentagon, the 23d Special Warfare Aviation Detachment was deployed to Vietnam in September 1962 for the purpose of providing air surveillance in support of Republic of Vietnam forces. In addition, they were to

serve as a test unit for operational evaluation conducted by the Army Concept Team in Vietnam. The 23d Special Warfare Aviation Detachment (Surveillance) was organized in July 1962 as a prototype armed aerial surveillance unit using the OV-1 Mohawk aircraft. Besides its headquarters and photo processing section, there were three flight teams, each consisting of two armed Mohawks, four pilots, and seven enlisted maintenance and armament specialists.

When they were deployed to Vietnam their rules of employment specified that: on all operational flights a Vietnamese observer would be aboard; that the aircraft would be armed with .50 caliber weapons only; and, that this armament would be used only when required to defend against a hostile attack. The 23d Special Warfare Aviation Detachment was assigned to Support Group, Vietnam for administration and logistical support. Operational control remained with Commander, Military Assistance Command, Vietnam, who decided to place the Mohawks in support of II Army of the Republic of Vietnam Corps. From 16 October to 22 November the entire unit was stationed at Nha Trang supporting the 9th Division and the Railway Security Agency. On 23 November one flight team was moved to Qui Nhon, 100 miles north of Nha Trang, to be closer to the 9th Division.

The plan of test for the 23d Special Warfare Aviation Detachment called for systematic surveillance of a sector that would insure an even distribution of effort over a selected tactical area. However, it soon became abundantly clear that the supported units were generating so many missions for specific reconnaissance sorties within their tactical areas that no other missions could be flown. In each area, an element of the 23d Special Warfare Aviation Detachment was employed under the direction of the Army of the Republic of Vietnam commander, through his U. S. advisor, as an integral part of the total available force. Because of the many variables involved, the specific contribution of the Mohawk to the reduction of Viet Cong incidents could not be quantified. But, there was no question that the 23d Special Warfare Aviation Detachment inhibited and restricted Viet Cong activity.

Visual and photographic reconnaissance by this twin-turbine airplane produced a wealth of intelligence for supported units. Hundreds of structures, most of them camouflaged, were detected in Viet Cong base areas. Likewise, hundreds of people were sighted in suspect areas and, because of the detailed familiarity of Mohawk crews with the local situation and activity patterns, some of the people sighted could be positively identified as insurgents. One of

the unique advantages of the Mohawk in reconnaissance was its speed to noise relationship which allowed the aircraft to get within observation distance of people on the ground without alerting them to it's presence. In one division, artillery fires directed from the air were nearly tripled by the activities of Mohawk observers. Supported units quickly developed air to ground procedures to exploit the capabilities of the immediately available Special Warfare Aviation Detachment aircraft.

From 16 October 1962 to 15 March 1963 the 23d Special Warfare Aviation Detachment flew more than 2,000 hours in the performance of 785 combat support missions. It had delivered defensive fire 27 times and had lost two aircraft. The cause of the loss of these two aircraft was never determined.

Many of the U. S. Army advisors wrote glowing reports of the Mohawk pilots and urged Military Assistance Command, Vietnam, to relax the rules of engagement. For example, on 23 March 1963 the Senior advisor of the II Corps Tactical Zone, Colonel Hal D. McCown, Wrote:

In another letter, dated 19 March 1963, the Senior Advisor of the 25th Army of the Republic of Vietnam Division, Colonel Paul A. Baldy, echoed many of Colonel McCown's remarks and added his own list of impressive data. He closed his letter with the following:

Similar letters of praise came from the 9th Infantry Division advisors and the senior railway security advisor. In the case of railway security, enemy attacks decreased by 50 percent after regular surveillance was begun by the 23d Special Warfare Aviation Detachment. Nevertheless, the career of a railway engineer in Vietnam was considered to be non-habit forming.

There is no doubt that the Mohawks filled a real intelligence need for the U. S. Army advisors in the field. For the first time the advisors found themselves with a responsive tool in the form of the Mohawk under their direct operational control to fill in the many gaps in their intelligence. Their requests for aerial surveillance and fighter strikes through the cumbersome channels to the Vietnamese Air Force no doubt increased their desire for more Mohawk support. As can be seen from the above, there was the inevitable trend to use the Mohawk in the fighter role, mainly because it was there and it had the hard points necessary to carry armament.

Having described earlier some of the controversial aspects that surrounded the procurement of the Caribou by the U. S. Army, I must now touch on its role in the early years in Vietnam. Unquestionably, the Caribou filled a serious gap in the United States inventory. Its short field characteristics, pay load, and light "footprint" made it an ideal aircraft in the counter-insurgency environment.

A not-well-known fact is that the Caribou airplane predated our major helicopter commitment to Vietnam by five months. On 21 August 1961, an experimental "Y model" Caribou landed at Saigon under the auspices of the Advanced Research Project Agency. The Advanced Research Project Agency had its own charter to test almost any device, technique, or prototype that it felt might have application in our counter-insurgency efforts. Consequently, the Agency was able to cut through the red tape of Service disagreements and expedite those tests it deemed appropriate.

The Advanced Research Project Agency Caribou flew tip and down the length of Vietnam going into airstrips normally limited to much smaller aircraft such as the O-1 or U-6 Beaver. Initially it specialized in resupply of Special Forces outposts that were in

accessible by road and that normally were supplied by either air drop or an occasional helicopter. In December 1961, while this aircraft was stationed at Da Nang, the Caribou was requested to support the Army of the Republic of Vietnam 2d Engineer Battalion which was attempting to improve the primitive airfield at A Shau. In view of the rainy season, the Vietnamese Air Force did not consider it suitable for either O-1 or U-6 aircraft; and, because of the constant cloud cover, air drops from C-47's were impossible. The Caribou navigated through the valleys to A Shau and landed on the wet primitive strip for the first time. Resupply parachutes from previous air drops and troops due for rotation were the first load out. The troops crowded to board the aircraft since none of them believed that the Caribou would dare to come back. However, the Caribou did return many times bringing rice, fresh food, and pierced steel planking to improve the runway. The loads of succeeding trips were dictated by priority, the weather always posing a threat. Finally, a complete road grader was moved in, 5,500 pounds at a time.

On December 17th, this Caribou took the President of the Republic of Vietnam and his official retinue into A Shau. Shortly thereafter, on Christmas Day, it landed President Ngo Dinh Diem and 37 additional passengers at a remote Montagnard outpost at Mang Buk in the II Corps Tactical Zone. This strip, not quite 1,000 feet long, was at an altitude of 4,000 feet and hemmed in by mountains. The Caribou had made an enviable reputation in Vietnam long before the first complete company of aircraft arrived in Southeast Asia.

On 23 July 1962, the 1st Aviation Company (Fixed-wing Light Transport) was self-deployed from the Continental United States to Thailand. In December the company was moved to Vung Tau, Republic of Vietnam. A second Caribou company, the 61st Aviation Company, was also self-deployed from the Continental United States in July 1963 and based at Vung Tau first. It was not until early 1963 that Commander in Chief Pacific approved the proposed test plan for the Caribou company, but by that time the Caribous had been integrated into most of the daily planning at the corps level.

The Army Caribou pilots took justifiable pride in their proficiency at bringing this big twin-engine airplane into the shortest possible strip. Even the old Southeast Asia hands of "Air America" were impressed when this lumbering bird made its unbelievably slow, steep approach into some of the primitive airstrips. The two following examples were typical.

Sixty-five miles southwest of Saigon and just one-half mile north of the Mekong River, the Cao Lanh airstrip resembled an aircraft carrier's deck about three feet out of water. It was typical of the Delta strips with one noteworthy exception-its runway was only 55 feet wide. Since the Caribou had a main gear track of approximately 26 feet, and since a five to ten knot cross wind usually prevailed at Cao Lanh, the pilots had to exercise extreme precise directional control prior to and immediately after touchdown. While maintaining sufficient airspeed to facilitate directional control, they had to constantly guard against coming in too fast on the short 1,300 foot runway. From May to September the shoulders of this airstrip were too wet and soft for the aircraft to leave the runway. Consequently, the Caribou pilot had to make a half turn at the end of the runway, then shut down the inside engine while the local Army of the Republic of Vietnam security force pushed the aircraft back for another start, and then complete his turn. Nevertheless, the Caribou flights served this strip three times a week.

Probably the shortest strip used consistently by the Caribou was Tra My in I Corps. Tra My was 830 feet long and lay in a valley floor requiring very steep descents and maximum performance climb-outs even for aerial delivery. At each end of the strip was an abrupt embankment. There was no room for a short landing or an overrun. The first landing was made by Captain Ephriam M. Goss and CWO P. Crossan. After three attempts, Captain Goss touched down twelve feet from the west embankment and came to a skidding halt eight feet from the east embankment. Needless to say, a hasty effort was made to lengthen the strip.

During the first six months of formal testing in early 1963, the Caribous flew 47,563 passengers and carried over 3,800 tons of cargo in over 9,000 sorties. Its availability rate was consistently high. It proved a boon to Army logistical support in Vietnam. General Rowny, who was in charge of the tests being run by the Army Concept Team in Vietnam, stated:

Like the Mohawk, the history of the Caribou is somewhat tangential to the history of airmobility in the Army. It did perform a logistics role in a gross weight and performance category that was unique. The next plane in size was the C-123B which had a gross weight of 55,700 pounds compared to the Caribou's 28,500 pounds, and the single wheel load of the C-123 was almost double that of the Caribou. Consequently, the Caribou could operate repeatedly and routinely into airfields that were denied to the C-123 and later the C-130. For example, in 1963, the Caribou could operate into 77 percent of all airstrips in Vietnam while the C-123 was limited to just 11 percent of these airfields. The big question at this time was whether the Caribou should be employed under the corps senior advisors or whether it should be integrated into the Southeast Asia airlift system. Strong differences of opinion existed.

In 1964 the 61st Aviation Company introduced the low-level extraction system to Vietnam. In this technique the Caribou flew over a restricted drop area, at an altitude of about ten feet, and a drag chute attached to the load which was to be deployed pulled the load out of the ship through the rear door. Faster than the time it takes to tell, the load skidded across the ground until it came to a safe rest. Using this system, a narrow stretch of road was an acceptable drop zone. During my visit to Vietnam in August 1964, the only complaint I heard about the Caribou was that there weren't enough of them.

At that time our fixed-wing aviation assets were centralized in Vietnam in the Aviation Support Battalion (Provisional) commanded by Lieutenant Colonel Robert J. Dillard. This battalion consisted of the 18th Aviation Company (U-1A Otters) for light transport, the 73d Aviation Company (O-1F Bird Dogs) for reconnaissance, the 61st Aviation Company (CV-2B Caribou) for heavy transport, and the 23d Special Warfare Aviation Detachment (JOV-1 Mohawk) for surveillance. Three transportation maintenance companies provided the necessary logistics support. The 18th Aviation Company with its Otters had been doing yeoman service in Vietnam since January 1962 and its pilots generally felt that their unique contribution to supplying infinitesimal air-

strips with everything from pigs and chickens to ammunition had been overlooked in the press attention to more exotic units. The lumbering Otters flew on and on with little maintenance and little credit.

Another unit which is seldom mentioned in the Vietnam reports (probably because it was so often taken for granted) was the 73d Aviation Company flying the two-place Bird Dog of Korean vintage. That company had arrived in Saigon on 23 May 1962 and its thirty-two aircraft were spread in fifteen separate locations all the way from Hue in the north to Bac Lieu in the south. These O-1's were primarily oriented to the reconnaissance requirement for the Vietnamese advisors but also were utilized for artillery adjustment, target acquisition, command and control, message pickup, medical evacuation, radio relay, and resupply. By 1964 this unit had set tip its own school to train the Vietnamese officers and aerial observers and they had recorded over 41,000 hours of flying time in their first fourteen months in Vietnam.

While I was in Saigon in the summer of 1964 I spent some time with Major General Oden, Commanding General of the U. S. Army Support Command in Vietnam. General Oden, who had been my predecessor as Director of Army Aviation, highlighted the increased intensity of combat in Vietnam and the concurrent increased risks being taken by our aviation units. It was apparent at this time that the most important aspect of U. S. support to the Army of the Republic of Vietnam was the capability embodied in our U. S. Army aviation organizations.

From the arrival of the first H-21's in December 1961 up to mid-1965, the U. S. Army had concentrated on developing airmobile operations in support of Army of the Republic of Vietnam forces in an ever-increasing scope. As the Allied tactics and techniques developed, so did the Viet Cong develop counter tactics and techniques. Consequently, there was always a need for innovation. Experience proved that any set pattern for any length of time was extremely dangerous since the Viet Cong were quick to capitalize on these patterns and strike at the weakest point.

Commander, Military Assistance Command, Vietnam, on 12 June 1965, indicated his concern of the number of helicopter assaults that had been ambushed by the Viet Cong in recent months and directed Brigadier General John Norton, Deputy Commander of U. S. Army Support Command, Vietnam, to study this problem.

General Norton directed each corps to make a special presentation on their helicopter operations at a critique on 5 and 6 July 1965. After the critique, separate study groups were formed to discuss in depth the enemy and the environment, airmobile operations from planning to execution, command and control and communications, and current and prospective material. The meeting served to summarize the problems of airmobility during this period and possible solutions for the future.

General Norton's group noted that the Viet Cong were increasing their efforts to counter friendly airpower with larger caliber weapons and many reports indicated the introduction of the 12.7-mm machine gun into South Vietnam. It was reasonable to expect heavier antiaircraft weapons up to 37-mm in size to be introduced within the next six months.

The Viet Cong had learned more than a bit about the method of operation of Free World Forces and could well determine probable landing zones and the number of troops which could be brought in by one lift. Their antiaircraft weapons were now being centrally controlled and coordinated to deny the use of the most desirable landing zones and thereby channelize the airmobile forces into landing zones chosen and covered by the Viet Cong. In the latter zones, the Viet Cong forces tried to maintain favorable odds of four to one to the amount of Army of the Republic of Vietnam forces available to react against them. Even in 1965 it was envisioned that soon airmobile operations would be opposed by division-size units.

Combat intelligence for airmobile operations was woefully inadequate due to a multitude of inadequacies in Army of the Republic of Vietnam intelligence combined with restrictions imposed in U.S.-Army of the Republic of Vietnam advisory relations. The increased activity of the enlarged Viet Cong forces made the staging areas of airmobile forces increasingly vulnerable to surprise attacks. Fuel and ammunition depots were prime targets.

Increasing Viet Cong interdiction of main ground supply routes and the resultant dependency on air-delivered supplies was imposing a severe burden on available air cargo capabilities. It became evident that special command control had to be vigorously applied to insure that critical air tonnage was not diluted by non-essential cargo.

General Norton's study group also highlighted one of the major problems of the early armed helicopters-the armed Huey because of its gross weight and additional drag, was slower than the troop-carrying transport helicopters that it escorted. This meant that

either the whole column slowed down or that the assault had to be timed so that the gun ships and troop ships rendezvoused just prior to landing. There was an immediate requirement for a faster armed escort helicopter which could maintain a speed of at least 150 knots. The urgency of this requirement was to force the Pentagon to reexamine its position on the introduction of an "interim" armed helicopter rather than wait for a totally new weapons system.²

In summary, in June of 1965, the U. S. Army found itself with a large commitment of airmobile resources supporting Republic of Vietnam Armed Forces- with an organization that had grown somewhat like Topsy. Tactics and techniques had been generated by the necessity of the moment, procedures had been hammered out of necessity, and equipment had been borrowed and jury-rigged. Airmobility had obviously kept the South Vietnamese forces in being, but the Viet Cong had become increasingly more sophisticated and were reinforced with large numbers of North Vietnamese regular troops. The U. S. Army aviators and crew chiefs had done a heroic job in the face of countless difficulties, but it was obviously time to develop a new order of magnitude of airmobility and regain the offensive. The President of the United States decided to commit major numbers of U. S. ground combat troops to the action.

The option open to the President in 1965 to deploy a significant U. S. airmobile force was only possible because certain events had occurred in the preceding years. To understand airmobility in Vietnam we must examine the gradual development of the concept in the United States. Before we proceed with this examination, I want to interject one important reminder. The airmobile concept had its roots in the necessity to counter a sophisticated enemy in Europe. The Howze Board had only touched on the counter-guerrilla possibilities and the Air Assault tests, which we will discuss next, centered around two conventional opposing forces. Vietnam was in the background, to be sure, but only as one of many contingencies—not the contingency.

2. A detailed discussion of the development of a "new" armed helicopter will be found on page 144 where we discuss the arrival of the Cobra in Vietnam. Here it is sufficient to note that by this time in 1965, the concept definition of an Advanced Aerial Fire Support System had evolved from a rather straight-forward compound helicopter to an ultra-sophisticated, all-weather, computerized weapons platform with a rigid rotor. It's my personal opinion that the original concept could have been developed and delivered in this time frame, if the requirement had not been unduly complicated by additional requirements that strained the state of the art, increased costs, and delayed delivery.

page updated 30 May 2001

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